Commit Graph

65 Commits

Author SHA1 Message Date
Vladislav Dzhidzhoev 6cf11f4462 [GlobalISel][DebugInfo] Salvage trivially dead instructions
Use salvageDebugInfo for instructions erased as trivially dead in
GlobalISel.

It would be helpful to implement support of G_PTR_ADD and G_FRAME_INDEX
in salvageDebugInfo in future in order to preserve more variable
location.

Reviewed by: arsenm

Differential Revision: https://reviews.llvm.org/D133986
2022-09-17 03:54:55 +03:00
serge-sans-paille ed98c1b376 Cleanup includes: DebugInfo & CodeGen
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D121332
2022-03-12 17:26:40 +01:00
Matt Arsenault 5a16306c09 GlobalISel: Always enable GISelKnownBits for InstructionSelect
This wasn't running at -O0, and causing crashes for AMDGPU. AMDGPU
needs this to match the addressing modes of stack access instructions,
which is even more important at -O0 than with optimizations.

It currently costs nothing to run ahead of time, so just always enable
it.
2022-01-12 18:57:24 -05:00
Jack Andersen f108c7f59d [GlobalISel] Allow DBG_VALUE to use undefined vregs before LiveDebugValues.
Expanding on D109750.

Since `DBG_VALUE` instructions have final register validity determined in
`LDVImpl::handleDebugValue`, there is no apparent reason to immediately prune
unused register operands as their defs are erased. Consequently, this renders
`MachineInstr::eraseFromParentAndMarkDBGValuesForRemoval` moot; gaining a
substantial performance improvement.

The only necessary changes involve making relevant passes consider invalid
DBG_VALUE vregs uses as valid.

Reviewed By: MatzeB

Differential Revision: https://reviews.llvm.org/D112852
2021-12-05 15:55:59 -05:00
Reid Kleckner 89b57061f7 Move TargetRegistry.(h|cpp) from Support to MC
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.

This allows us to ensure that Support doesn't have includes from MC/*.

Differential Revision: https://reviews.llvm.org/D111454
2021-10-08 14:51:48 -07:00
Amara Emerson 6bc64e24c3 [GlobalISel] Clear unreachable blocks' contents after selection.
If these blocks are unreachable, then we can discard all of the instructions.
However, keep the block around because it may have an address taken or the
block may have a stale reference from a PHI somewhere. Instead of finding
those PHIs and fixing them up, just leave the block empty.

Differential Revision: https://reviews.llvm.org/D111201
2021-10-05 23:06:22 -07:00
Amara Emerson de5b16d8ca Revert "Revert "Revert "[GlobalISel][IRTranslator] Emit trap intrinsic for "unreachable""""
This reverts commit c93bc508ee.

Seems to break a different thing now.
2021-10-05 08:25:13 -07:00
Amara Emerson c93bc508ee Revert "Revert "[GlobalISel][IRTranslator] Emit trap intrinsic for "unreachable"""
This reverts commit d95cd81141.

The selector sometimes leaves unreachable blocks unselected because it uses a
postorder traversal for the block ordering.

With the trap intrinsics now being emitted, these blocks are no longer empty and
the unselected G_INTRINSIC instructions survive past selection. To fix this,
keep track of which blocks are selected and later delete any blocks that weren't
selected.
2021-10-04 18:10:28 -07:00
Amara Emerson 8a316045ed [AArch64][GlobalISel] Enable use of the optsize predicate in the selector.
To do this while supporting the existing functionality in SelectionDAG of using
PGO info, we add the ProfileSummaryInfo and LazyBlockFrequencyInfo analysis
dependencies to the instruction selector pass.

Then, use the predicate to generate constant pool loads for f32 materialization,
if we're targeting optsize/minsize.

Differential Revision: https://reviews.llvm.org/D97732
2021-03-02 12:55:51 -08:00
Jessica Paquette 4809663334 [GlobalISel] Make sure G_ASSERT_ZEXT's src ends up with the same rc as dst
When replacing the dst reg with the src reg, we need to make sure that we
propagate the dst reg's register class through to the src.

Otherwise, we aren't meeting the requirements for G_ASSERT_ZEXT, and so the
verifier will fail.

Differential Revision: https://reviews.llvm.org/D95708
2021-02-01 09:46:35 -08:00
Jessica Paquette d6656c3b25 [GlobalISel] Remove hint instructions in generic InstructionSelect code.
I think every target will want to remove these in the same way. Rather than
making them all implement the same code, let's just put this in
InstructionSelect.

Differential Revision: https://reviews.llvm.org/D95652
2021-01-29 11:20:07 -08:00
Kazu Hirata 12fc9ca3a4 [llvm] Remove redundant string initialization (NFC)
Identified with readability-redundant-string-init.
2021-01-12 21:43:46 -08:00
Matt Arsenault 521ebc1681 GlobalISel: Move finalizeLowering call later
This matches the DAG behavior where this is called after the loop
checking for calls. The AMDGPU implementation depends on knowing if
there are calls in the function or not, so move this later.

Another problem is finalizeLowering is actually called twice; I was
seeing weird inconsistencies since the first call would produce
unexpected results and the second run would correct them in some
contexts. Since this requires disabling the verifier, and it's useful
to serialize the MIR immediately after selection, FinalizeISel should
probably not be a real pass.
2020-07-06 09:19:40 -04:00
Simon Pilgrim fe0006c882 TargetLowering.h - remove unnecessary TargetMachine.h include. NFC
Replace with forward declaration and move dependency down to source files that actually need it.

Both TargetLowering.h and TargetMachine.h are 2 of the most expensive headers (top 10) in the ClangBuildAnalyzer report when building llc.
2020-05-23 19:49:38 +01:00
David Stenberg 6a2413c435 [ARM64] Debug info for structure argument missing DW_AT_location
Summary:
Prevent eliminating dbg_val due to COPY.

Fixes this
https://bugs.llvm.org/show_bug.cgi?id=40709

Patch by: Kamlesh Kumar (kamleshbhalui)

Reviewers: aprantl, dblaikie, vsk, dsanders

Reviewed By: dsanders

Subscribers: dstenb, kristof.beyls, hiraditya, llvm-commits

Tags: #debug-info, #llvm

Differential Revision: https://reviews.llvm.org/D73159
2020-01-29 10:56:23 +01:00
Amara Emerson 7ac1039957 [GlobalISel] Defer setting HasCalls on MachineFrameInfo to selection time.
We currently always set the HasCalls on MFI during translation and legalization if
we're handling a call or legalizing to a libcall. However, if that call is later
optimized to a tail call then we don't need the flag. The flag being set to true
causes frame lowering to always save and restore FP/LR, which adds unnecessary code.

This change does the same thing as SelectionDAG and ports over some code that scans
instructions after selection, using TargetInstrInfo to determine if target opcodes
are known calls.

Code size geomean improvements on CTMark:
 -O0 : 0.1%
 -Os : 0.3%

Differential Revision: https://reviews.llvm.org/D67868

llvm-svn: 372443
2019-09-20 23:52:07 +00:00
Matt Arsenault 466ec2d552 GlobalISel: Fix missing pass dependency
llvm-svn: 370496
2019-08-30 17:41:58 +00:00
Matt Arsenault caff0a88dd GlobalISel: Add known bits to InstructionSelector
AMDGPU uses this for some addressing mode selection patterns. The
analysis run itself doesn't do anything so it seems easier to just
always require this than adding a way to opt in.

llvm-svn: 370388
2019-08-29 17:24:32 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +00:00
Amara Emerson e14c91b71a [GlobalISel] Make the InstructionSelector instance non-const, allowing state to be maintained.
Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.

AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.

Differential Revision: https://reviews.llvm.org/D65984

llvm-svn: 368652
2019-08-13 06:26:59 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
Tom Stellard 1f7f64665c GlobalISel: Remove redundant pass initialization
Summary:
All the GlobalISel passes are initialized when the target calls
initializeGlobalISel(), so we don't need to call the initializers
from the pass constructors.

Reviewers: qcolombet, t.p.northover, paquette, dsanders, aemerson, aditya_nandakumar

Reviewed By: aemerson

Subscribers: rovka, kristof.beyls, hiraditya, volkan, Petar.Avramovic, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63235

llvm-svn: 363642
2019-06-18 02:05:06 +00:00
Amara Emerson 7097e83dab [GlobalISel] Make isel verification checks of vregs run under NDEBUG only.
llvm-svn: 356309
2019-03-16 01:02:10 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Matthias Braun 90ad6835dd CodeGen: Remove pipeline dependencies on StackProtector; NFC
This re-applies r336929 with a fix to accomodate for the Mips target
scheduling multiple SelectionDAG instances into the pass pipeline.

PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336964
2018-07-13 00:08:38 +00:00
Matthias Braun f03f32d478 Revert "(HEAD -> master, origin/master, arcpatch-D37582) CodeGen: Remove pipeline dependencies on StackProtector; NFC"
This was triggering pass scheduling failures.

This reverts commit r336929.

llvm-svn: 336934
2018-07-12 19:27:01 +00:00
Matthias Braun 9436570cbd CodeGen: Remove pipeline dependencies on StackProtector; NFC
PrologEpilogInserter and StackColoring depend on the StackProtector analysis
being alive from the point it is run until PEI, which requires that they are all
scheduled in the same FunctionPassManager. Inserting a (machine) ModulePass
between StackProtector and PEI results in these passes being in separate
FunctionPassManagers and the StackProtector is not available for PEI.

PEI and StackColoring don't use much information from the StackProtector pass,
so transfering the required information to MachineFrameInfo is cleaner than
keeping the StackProtector pass around. This commit moves the SSP layout
information to MFI instead of keeping it in the pass.

This patch set (D37580, D37581, D37582, D37583, D37584, D37585, D37586, D37587)
is a first draft of the pagerando implementation described in
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113794.html.

Patch by Stephen Crane <sjc@immunant.com>

Differential Revision: https://reviews.llvm.org/D49256

llvm-svn: 336929
2018-07-12 18:33:32 +00:00
Roman Tereshin 13229aff54 [GlobalISel] NFCI, Getting GlobalISel ~5% faster
by replacing DenseMap with IndexedMap for LLTs within MRI, as
benchmarked by cross-compiling sqlite3 amalgamation for AArch64
on x86 machine.

Reviewed By: qcolombet

Differential Revision: https://reviews.llvm.org/D46809

llvm-svn: 333125
2018-05-23 21:12:02 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Roman Tereshin 38489ed416 [GlobalISel] Reporting rules covered as part of the InstructionSelect's debug-only printing
The main goal of this change is to make it much easier to track which
rules are actually covered by Testgen'erated regression tests.

Reviewers: aemerson, dsanders

Differential Revision: https://reviews.llvm.org/D46095

llvm-svn: 330988
2018-04-26 20:22:17 +00:00
Roman Tereshin 2b94972eb9 [GlobalISel][AArch64] Adding -disable-gisel-legality-check CL option
Currently it's impossible to test InstructionSelect pass with MIR which
is considered illegal by the Legalizer in Assert builds. In early stages
of porting an existing backend from SelectionDAG ISel to GlobalISel,
however, we would have very basic CallLowering, Legalizer, and
RegBankSelect implementations, but rather functional Instruction Select
with quite a few patterns selectable due to the semi-automatic porting
process borrowing them from SelectionDAG ISel.

As we are trying to define legality as a property of being selectable by
the instruction selector, it would be nice to be able to easily check
what the selector can do in its current state w/o the legality check
provided by the Legalizer getting in the way.

It also seems beneficial to have a regression testing set up that would
not allow the selector to silently regress in its support of the MIR not
supported yet by the previous passes in the GlobalISel pipeline.

This commit adds -disable-gisel-legality-check command line option to
llc that disables those legality checks in RegBankSelect and
InstructionSelect passes.

It also adds quite a few MIR test cases for AArch64's Instruction
Selector. Every one of them would fail on the legality check at the
moment, but will select just fine if the check is disabled. Every test
MachineFunction is intended to exercise a specific selection rule and
that rule only, encoded in the MachineFunction's name by the rule's
number, ID, and index of its GIM_Try opcode in TableGen'erated
MatchTable (-optimize-match-table=false).

Reviewers: ab, dsanders, qcolombet, rovka

Reviewed By: bogner

Subscribers: kristof.beyls, volkan, aditya_nandakumar, aemerson,
rengolin, t.p.northover, javed.absar, llvm-commits

Differential Revision: https://reviews.llvm.org/D42886

llvm-svn: 326396
2018-03-01 00:27:48 +00:00
Roman Tereshin 3054ecea3f [GlobalISel] Print/Parse FailedISel MachineFunction property
FailedISel MachineFunction property is part of the CodeGen pipeline
state as much as every other property, notably, Legalized,
RegBankSelected, and Selected. Let's make that part of the state also
serializable / de-serializable, so if GlobalISel aborts on some of the
functions of a large module, but not the others, it could be easily seen
and the state of the pipeline could be maintained through llc's
invocations with -stop-after / -start-after.

To make MIR printable and generally to not to break it too much too
soon, this patch also defers cleaning up the vreg -> LLT map until
ResetMachineFunctionPass.

To make MIR with FailedISel: true also machine verifiable, machine
verifier is changed so it treats a MIR-module as non-regbankselected and
non-selected if there is FailedISel property set.

Reviewers: qcolombet, ab

Reviewed By: dsanders

Subscribers: javed.absar, rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D42877

llvm-svn: 326343
2018-02-28 17:55:45 +00:00
Aditya Nandakumar f2aa2af24e [GISel]: Remove redundant copies at the end of ISel
https://reviews.llvm.org/D42402

A lot of these copies are useless (copies b/w VRegs having the same
regclass) and should be cleaned up.

llvm-svn: 323291
2018-01-24 01:35:26 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
All these headers already depend on CodeGen headers so moving them into
CodeGen fixes the layering (since CodeGen depends on Target, not the
other way around).

llvm-svn: 318490
2017-11-17 01:07:10 +00:00
Daniel Sanders f76f315436 [globalisel][tablegen] Generate rule coverage and use it to identify untested rules
Summary:
This patch adds a LLVM_ENABLE_GISEL_COV which, like LLVM_ENABLE_DAGISEL_COV,
causes TableGen to instrument the generated table to collect rule coverage
information. However, LLVM_ENABLE_GISEL_COV goes a bit further than
LLVM_ENABLE_DAGISEL_COV. The information is written to files
(${CMAKE_BINARY_DIR}/gisel-coverage-* by default). These files can then be
concatenated into ${LLVM_GISEL_COV_PREFIX}-all after which TableGen will
read this information and use it to emit warnings about untested rules.

This technique could also be used by SelectionDAG and can be further
extended to detect hot rules and give them priority over colder rules.

Usage:
* Enable LLVM_ENABLE_GISEL_COV in CMake
* Build the compiler and run some tests
* cat gisel-coverage-[0-9]* > gisel-coverage-all
* Delete lib/Target/*/*GenGlobalISel.inc*
* Build the compiler

Known issues:
* ${LLVM_GISEL_COV_PREFIX}-all must be generated as a manual
  step due to a lack of a portable 'cat' command. It should be the
  concatenation of all ${LLVM_GISEL_COV_PREFIX}-[0-9]* files.
* There's no mechanism to discard coverage information when the ruleset
  changes

Depends on D39742

Reviewers: ab, qcolombet, t.p.northover, aditya_nandakumar, rovka

Reviewed By: rovka

Subscribers: vsk, arsenm, nhaehnle, mgorny, kristof.beyls, javed.absar, igorb, llvm-commits

Differential Revision: https://reviews.llvm.org/D39747

llvm-svn: 318356
2017-11-16 00:46:35 +00:00
Matthias Braun 4682ac6c83 ARM: Compute MaxCallFrame size early
This exposes a method in MachineFrameInfo that calculates
MaxCallFrameSize and calls it after instruction selection in the ARM
target.

This avoids
ARMBaseRegisterInfo::canRealignStack()/ARMFrameLowering::hasReservedCallFrame()
giving different answers in early/late phases of codegen.

The testcase shows a particular nasty example result of that where we
would fail to properly align an alloca.

Differential Revision: https://reviews.llvm.org/D32622

llvm-svn: 302303
2017-05-05 22:04:05 +00:00
Krzysztof Parzyszek 44e25f37ae Move size and alignment information of regclass to TargetRegisterInfo
1. RegisterClass::getSize() is split into two functions:
   - TargetRegisterInfo::getRegSizeInBits(const TargetRegisterClass &RC) const;
   - TargetRegisterInfo::getSpillSize(const TargetRegisterClass &RC) const;
2. RegisterClass::getAlignment() is replaced by:
   - TargetRegisterInfo::getSpillAlignment(const TargetRegisterClass &RC) const;

This will allow making those values depend on subtarget features in the
future.

Differential Revision: https://reviews.llvm.org/D31783

llvm-svn: 301221
2017-04-24 18:55:33 +00:00
Ahmed Bougacha 15b3e8a93a [GlobalISel] Update DBG_VALUEs referencing DCE'd instructions.
Quentin points out that r298358 would cause us to emit different code
with debug info.  That's a big no-no; also erase the instructions that
only live thanks to DBG_VALUE users.

Adrian explained how this is an existing problem and an OK thing to do:
clang has allocas for all variables so shouldn't be affected at -O0, but
swift uses a bit of inlineasm to explicitly keep values live for the
purpose of debug info quality.  I'm not sure there is a better scheme.

llvm-svn: 298460
2017-03-21 23:42:54 +00:00
Volkan Keles 47debaeef0 [GlobalISel] Move isTriviallyDead to Utils. NFC.
Make it accessible by the targets to avoid code duplication.

llvm-svn: 298358
2017-03-21 10:47:35 +00:00
Ahmed Bougacha 931904d777 [GlobalISel] Don't select trivially dead instructions.
Folding instructions when selecting can cause them to become dead.
Don't select these dead instructions (if they don't have other side
effects, and don't define physical registers).

Preserve existing tests by adding COPYs.

In some tests, the G_CONSTANT vregs never get constrained to a class:
the only use of the vreg was folded into another instruction, so the
G_CONSTANT, now dead, never gets selected.

llvm-svn: 298224
2017-03-19 16:13:00 +00:00
Ahmed Bougacha 7f2d17331c [GlobalISel] Move method definition to the proper file. NFC.
llvm-svn: 298221
2017-03-19 16:12:48 +00:00
Tim Northover ef29e7284b GlobalISel: check for CImm rather than Imm on G_CONSTANTs.
All G_CONSTANTS created by the MachineIRBuilder have an operand of type CImm
(i.e. a ConstantInt), so that's what the selector needs to look for.

llvm-svn: 296176
2017-02-24 21:21:38 +00:00
Daniel Sanders 066ebbfd46 [globalisel] Decouple src pattern operands from dst pattern operands.
Summary:
This isn't testable for AArch64 by itself so this patch also adds
support for constant immediates in the pattern and physical
register uses in the result.

The new IntOperandMatcher matches the constant in patterns such as
'(set $rd:GPR32, (G_XOR $rs:GPR32, -1))'. It's always safe to fold
immediates into an instruction so this is the first rule that will match
across multiple BB's.

The Renderer hierarchy is responsible for adding operands to the result
instruction. Renderers can copy operands (CopyRenderer) or add physical
registers (in particular %wzr and %xzr) to the result instruction
in any order (OperandMatchers now import the operand names from
SelectionDAG to allow renderers to access any operand). This allows us to
emit the result instruction for:
  %1 = G_XOR %0, -1 --> %1 = ORNWrr %wzr, %0
  %1 = G_XOR -1, %0 --> %1 = ORNWrr %wzr, %0
although the latter is untested since the matcher/importer has not been
taught about commutativity yet.

Added BuildMIAction which can build new instructions and mutate them where
possible. W.r.t the mutation aspect, MatchActions are now told the name of
an instruction they can recycle and BuildMIAction will emit mutation code
when the renderers are appropriate. They are appropriate when all operands
are rendered using CopyRenderer and the indices are the same as the matcher.
This currently assumes that all operands have at least one matcher.

Finally, this change also fixes a crash in
AArch64InstructionSelector::select() caused by an immediate operand
passing isImm() rather than isCImm(). This was uncovered by the other
changes and was detected by existing tests.

Depends on D29711

Reviewers: t.p.northover, ab, qcolombet, rovka, aditya_nandakumar, javed.absar

Reviewed By: rovka

Subscribers: aemerson, dberris, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D29712

llvm-svn: 296131
2017-02-24 15:43:30 +00:00
Ahmed Bougacha 7c88a4e12b [GlobalISel] Use the DISubprogram for translation failure remarks.
Justin added support for DISubprogram locs in r295531 and r296052.
Use that instead of no-loc for constants and arguments.

llvm-svn: 296058
2017-02-24 00:34:44 +00:00
Ahmed Bougacha ae9dadecf3 [GlobalISel] Emit opt remarks on isel fallbacks.
Having more fine-grained information on the specific construct that
caused us to fallback is valuable for large-scale data collection.

We still have the fallback warning, that's also used for FastISel.
We still need to remove the fallback warning, and teach FastISel to also
emit remarks (it currently has a combination of the warning, stats, and
debug prints: the remarks could unify all three).

The abort-on-fallback path could also be better handled using remarks:
one could imagine a "-Rpass-error", analoguous to "-Werror", which would
promote missed/failed remarks to errors.  It's not clear whether that
would be useful for other remarks though, so we're not there yet.

llvm-svn: 296013
2017-02-23 21:05:42 +00:00
Ahmed Bougacha 1b3339447d [GlobalISel] Simplify Select type cleanup using a ScopeExit. NFC.
This lets us use more natural early-returns when selection fails.

llvm-svn: 296006
2017-02-23 19:17:24 +00:00
Tim Northover c94d70336b GlobalISel: tidy up def/use test. NFC.
llvm-svn: 293545
2017-01-30 20:52:37 +00:00
Tim Northover 480609d0f3 GlobalISel: permit unused vregs without a register-class after ISel.
This can happen if earlier combining has removed all uses of some VReg, which
is fine and shouldn't flag an error.

llvm-svn: 293537
2017-01-30 19:12:50 +00:00
Justin Bogner 4844573eb1 GlobalISel: Fix typo in error message
llvm-svn: 293023
2017-01-25 06:02:10 +00:00